Combined cinder collector and fluid heater



2 Sheets-Sheet 1 .l'larzil'Ce T. B. ALLARDICE Filed Nov. 29, 1939 R 0B Mm 0 6 b 2 Tm u 5 0 4 ATTORN EY March 25, 1941.

COMBINED CINDER COLLECTOR AND FLUID HEATER March 25, 1941- T. B. ALLARDICE COMBINED CINDER COLLECTOR AND FLUID HEATER Filed Nov. 29, 1959 2 Sheets-Sheet 2 G-aa 39 40 Q1- IFIIJIII ILO Thomas B. flllardz'te ATTORNEY Patented Mar. 25, 1941 UNITED STATES PATENT OFFICE COMBINED CINDER COLLECTOR AND FLUID HEATER This invention relates to combined cinder or dust collectors and fluid heaters, and relates more particularly to apparatus for collectin solid matter from flue gases from, for example,

5 steam power plants, and for extracting heat from the flue gases, and for utilizing the extracted heat for heating air or water.

An object of the invention is to flow the fluid to be heated through tubes and to flow the heat- 10 ed gases in spiral paths around the tubes.

Another object of the invention is to provide an emcient collector in which the solid particles are thrown out of the flue gases by centrifugal force.

15 Another object of the invention is to provide an eflicient, compact, cinder collector and fluid heater.

The invention will now be described with reference to the drawings, of which:

20 Fig. 1 is a side elevational view, in cross-section of a combined cinder collector and fluid heater embodying this invention;

Fig. 2 is an enlarged sectional view of one of the heat exchange and cinder separating tube 25 assemblies of Fig. 1;

Fig. 3 is a side elevational view, in cross-section, of another form of cinder collector and fluid heater embodying this invention;

Fig. 4 is a side elevational view, in cross-sec- 30 tion, of another form of cinder collector and fluid heater embodying this invention;

Fig. 5 is a partial section taken along the lines 5-5 of Fig. 1, and

Fig. 6 is a sectional view along the lines 6-5 35 of Fig. 2.

Referring first to Figs. 1, 2 and 5, which illustrate a combined cinder collector and fluid heater of the vertical flow type, the inner tubes l which are adapted to receive the fluid to be 40 heated, extend centrally through the outer tubes II which in turn, are adapted to receive the heated flue gases.

The outer tubes ll terminate at their lower ends in the V-shaped floor l2 of the collector,

45 which is apertured to receive the tubes II. The

upper ends of the tubes ll terminate in the horizontal wall l3 which is apertured to receive them.

The inner tubes Ill extend above and below the 50 tubes ll. Their lower ends terminate in the lower wall M which is apertured to receive them, and their upper ends terminate in the upper wall l which is apertured to receive them.

The tubes l0 and II are divided into two 55 groups by the inner walls l6 which extend from the horizontal wall l3, through the floor l2 and lower wall I4 and which are spaced apart to form the cinder hopper II in their lower portions.

As shown most clearly by Fig. 2, each tube ID has wound spirally around it in that portion 5 of the tube which is contained within its respective outer tube II, the metalstrip ill, the inner edges of which contact the tubes I0, and the outer edges of which contact the inner surfaces of the tubes Ii. At spaced intervals, the walls 10 of the tubes II are cut and spread at I9 to formthe slits 20.

The heated flue gases from the gas inlet 2| pass in contact with the lower ends of the tubes H) which are placed to the left (facing Fig. 1 of the drawings) of the walls It, then enter the lower ends of the tubes H, which surround the last mentioned tubes "I.

The flue gases leaving the upper ends of the last mentioned tubes ll pass in contact with the upper ends of the tubes l0 and then enter the upper ends of the tubes H which .are arranged to the right of the walls It. The flue gases then descend within the last mentioned tubes II and pass out their lower 'ends in contact with the lower ends of the tubes III which are arranged to the right of the walls l6, and then out the gas exit 22.

The fluid to be heated flows through the fluid inlet 23 into the lower ends of the tubes I0 to the right of the walls l6, passes out their upper ends into the upper ends of the tubes [0 to the left of the walls-I6 and then out their lower ends into the fluid exit 24. This counter-current flow of the fluid and thegas with the coldest fluid passing in heat exchange contact with the coldest gas, provides maximum efliciency.

The strips l8 within the tubes ll cause the flue gases to pass spirally within the tubes H and around the tubes III. This provides increased contact time and conformably increased heat transfer from the gases to the fluid flowing through the tubes Ill.

The cinders and dust, etc., in the flue gases due to their spiral path are forced by centrifugal force against the inner surfaces of the tubes II and at the slots 20 are thrown out the tubes ll into the space surrounding them. The solid matter thus thrown out of the tubes ll falls upon the converging walls of the floor [2, slides down the sloped walls and passes through the openings 25 in the walls It at the apex of the- V-shaped floor l2, into'the cinder hopper ll.

The cinder hopper I1 is, of courseanorlmally closed at its lower end for permitting the ac- 5 cumulation of cinders which may be removed at intervals. The space within the hopper I1 is connected by the tube 25, shown in dotted outline by Fig. 1, with the gas exit 22. The inlet 26 of the tube 25 is in the hopper space and its outlet 21 is in the gas exit 22. The damper 28 in the tube regulates the pressure in the hopper. With the dampers 28 closed, the space within the hopper is dead so that no circulation can take place therein and no gas can leave the slots 20 in the tubes II to enter the hop r space. With the damper moved towards open position, gas circulation through the hopper is permitted to aid in ejection of the solid matter from the slots 20 in the tubes H.

In the embodiment illustrated by Fig. 3, the fluid heater section and the collector section are separate and the tubes are arranged horizontally. The flue gases enter through the gas inlet 29, pass over the exterior of the fluid heater tubes 30, and then turn through an angle of 180 to pass through the collector tubes 3|. The gases leaving the tubes 3| turn through an angle of into the gas exit 32.

The fluid to be heated enters the tubes 30 from the fluid inlet 4| and after passing through the tubes 30, departs through the fluid exit 42.

The hopper 33 has the converging walls 34 extending below the tubes 30 and 3|. The hopper 33 has a portion 35 connecting with the gas at the entrance to the tubes 3|, with adjustable damper 36 for permitting a portion of the gas to pass through the tubes 3| or into the hopper.

The tube 31 with inlet 38 in the hopper 33 and outlet 39 in the gas exit 32 permits circulation controllable by the damper 43, of gas through the hopper.

The collector tubes 3| contain spirally wound strips 4| similar to the strips ll of Figs. 1 and 2 except that no inner tubes pas therethrough and serve to cause the gases posing through the tubes 3| to move spirally through the tubes and the solid matter carried thereby to be thrown by centrifugal force against the inner surfaces of the tubes 3|. The walls of the tubes 3| have the spaced, out, extruded portions 42 which provide slots similar to the slots 20 of Figs. 2 and 6 and which permit exit of the solid matter thrown out by centrifugal force from the tubes 3|.

The tube sheet 43 extends vertically and encloses the inlet ends of the tubes 3| and the similar tube sheet 44 encloses the outlet ends of the tubes 3|.

The embodiment illustrated by Fig. 4, is similar to that illustrated by Fig. 3 except that the collector tubes also contain fluid heating tubes, the fluid to be heated flows in two passes, and the tube sheet enclosing the exit ends of the collector tubes forms an extension of one of the converging walls of the hopper instead of extending vertically. Accordingly, similar structure in Figs. 3 and 4 is provided with the same reference characters.

In the embodiment of Fig. 4, the collector tubes 3| contain additional fluid heating tubes 45 around which the spiral strips 4| are wound, and the gas leaving the fluid heating tubes 30 passes over and around the additional fluid heating tubes 45.

The fluid inlet 4| is arranged at the entrance of the additional fluid heater tubes 45, and the fluid leaving the tubes 45 makes a tum and enters the inlet ends of the tubes 33.

The tube sheet 43 enclosing the outlet ends of the tubes 3| forms an extension 01' the enclosed left hand wall 34 (facing Fig. 4 of the drawings) and deflects as do the walls 34, solid matter thrown out from the tubes 3|, into the hopper 33.

While embodiments of the invention have been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangements of apparatus illustrated, as departures therefrom may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

1. A combined fluid heater and cinder collector, comprising a plurality of inner tubes, a plurality of larger outer tubes arranged substantially concentrically around said inner tubes, metal strips wound spirally around said inner tubes, means for flowing a fluid to be heated through said inner tubes, means for flowing heated gases through said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gastubes, means for flowing a fluid to be heated through said inner tubes, means forming a heated gas inlet passage into said outer tubes, means forming a gas outlet passage from said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, a cinder hopper below said outer tubes for receiving the cinders, means forming a gas circulation passage connecting the interior of said hopper and said outlet passage, and a damper in said circulation passage for varying the circulation of gas through said hopper.

3. A combined fluid heater and cinder collector comprising a plurality of inner tubes, a plurality of larger outer tubes arranged substantially concentrically around portions of said inner tubes, means for flowing a fluid to be heated through said inner tubes, means forming gas inlet passages into, and gas outlet passages from, said outer tubes, said outer tubes having ends terminating in inner walls of said passages, said inner tubes having portions extending through said walls and cross-wise said passages, metal strips wound spirally around said portions of said inner tubes within said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, and a cinder hopper below said outer tubes.

4. A combined fluid heater and cinder collector comprising a plurality of inner tubes, a plurality of larger outer tubes arranged substantially concentrically around portions of said inner tubes, means for flowing a fluid to be heated through said inner tubes, means forming gas inlet passages into, and gas outlet passages from, said outer tubes, said outer tubes having ends terminating in inner walls of said passages, said inner tubes having portions extending through said walls and cross-wise said passages, metal strips wound spirally around said portions of said inner tubes within said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, and a cinder hopper having converging walls below said outer tubes, one of said inner walls 'forming an extension of one of said converging walls.

5. A combined fluid heater and cinder collector comprising a plurality of inner tubes, a plurality of larger outer tubes arranged substantially concentrically around portions of said in-- ner tubes, means for flowing a fluid to be heated through said inner tubes, means forming gas inlet passages into, and gas outlet passages from, said outer tubes, said outer tubes having ends terminating in inner walls of said passages, said inner tubes having portions extending through said walls and cross-wise said passages, metal strips wound spirally around said portions of said inner tubes within said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting fromthe gas flow around said strips, and a cinder hopper having converging walls below said outer-tubes, saidinner wall of said gas inlet-passage forming an extension of one of saidconverging walls 6. A combined fluid heater and cinder collector comprising a plurality of inner tubes, a plurality of larger outer tubes arranged substantially concentrically around portions of said inner tubes, means for flowing a fluid to be heated through said inner tubes, means including converging innerwalls forming gas inlet passages into, and

gas outlet passages from, said outer tubes, said outer tubes having ends terminating in said converging walls, said inner tubes having portions extending through said walls and cross-wise said passages, metal strips wound spirally around said portions of said inner tubes within said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, and a cinder hopper having converging walls forming extensions of said first mentioned converging walls below said tubes. a

'l. A combined fluid heater and cinder collector, comprising a plurality of substantially vertical outer tubes, spaced substantially vertical walls dividing said tubes into two groups, a pair of converging walls, one enclosing the lower ends of the tubes of one of said groups and the other enclosing the ends of the tubes of the other of said groups, substantially smaller inner tubes arranged substantially concentrically within said outer tubes, metal strips wound spirally around said inner tubes, means for flowing a fluid to be heated through said inner tubes, and means for flowing heated gases through said outer tubes, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, said vertical walls extending through said converging walls and forming a cinder hopper therebeneath and having openings at the lower ends of said converging walls for receiving cinders therefrom.

8. A combined fluid heater and cinder collector, comprising a plurality of substantially vertical outer tubes, spaced substantially vertical walls dividing said tubes into two groups, a pair of converging walls, one enclosing the lower ends of the tubes of one of said groups and the other enclosing the ends or the tubes. of the other of said groups, substantially smaller inner-tubes arranged substantially concentrically within said outer tubes, metal strips wound spirally around said inner tubes, means for flowing a fluid to be heated through said inner tubes, means forming a heated gas inlet passage for supplying gas through one of said converging walls into the lower ends of the tubes of one of said groups, means forming an upper passage for guiding the gas leaving the upper ends of the tubes of said group into th upper ends of the tubes of said other group, and means forming a gas outlet passage from the lower endsof the tubes of said other of said groups, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, said vertical'walls extending through said converging walls and forming a cinder hopper therebeneath and having openings at the lower ends of said converging walls for receiving cinders therefrom. l

9, A combined fluidheater and cinder collector, comprising a plurality of substantially vertical outer tubes, spaced substantially vertical walls dividing said tubes into two groups, a pair of converging walls, oneenclosing the lower ends of the tubes of one of said groups and the other enclosing the ends of the tubes of the other of said groups, substantially smaller inner tubes arranged substantially concentrically within said outer tubes, metal strips wound spirally around said inner tubes,'means for flowing a fluid to be heated through said inner tubesmeans forming a heated gas inlet passage for supplying gas through one of said converging walls into the lower ends of the tubes of one of said groups,

means forming an upper passage for guiding the gas leaving the upper ends of the tubes of said group into the upper ends of the tubes of said other group, and means forming a gas outlet pas-' sage from the lower ends of the tubes of said other of said groups, the walls of said outer tubes having openings formed therein for the ejection of cinders thrown out by the centrifugal force resulting from the gas flow around said strips, said vertical walls extending through said converging tical outer tubes, spaced substantially vertical walls dividing said tubes into two groups, a pair of converging walls, one enclosing the lower ends of the tubes of one of said groups and the other enclosing the ends of the tubes of the other of said groups, substantially smaller inner tubes arranged substantially concentrically within said outer tubes, metal strips wound spirally around said inner tubes, means for flowing a fluid to be heated through said inner tubes, means forming a heated gas inlet passage for supplying gas through one of said converging walls into the lower ends of the tubes of one of said groups, means forming an upper passage for guiding the gas leaving the upper ends of the tubes of said group into the upper ends of the tubes of said other group, and means forming a gas outlet passage from the lower ends of the tubes of said other of said groups, the walls of said outer tubes having openings formed therein for the election 01' cinders thrown out by the centrifugal force resulting from the gas flow around said strips. said vertical walls extending through said converging walls and iorming a cinder hopper therebeneath and having openings at the lower ends oi. said converging walls for receiving cinders therefrom, said inner tubes having lower extensions extending through said converging walls crosswise said inlet andoutiet passages and having upper extensions extending crosswise said upper e.

11. A combined fluid heater and cinder col lector, comprising a plurality of substantially par. allel, horizontal fluid heater tubes, a wall dividing said tubes into upper and lower gro p substantially larger outer tubes arranged substantially concentrically around the tubes 01' said lower group, a cinder hopper below said outer tubes, metal strips wound spirally around the tubes of said lower group and between same and their respective outer tubes, means for flowing a fluid to be heated flrst through said tubes of said lower group and then through said tubes said upper group, and means forming gas passages for flowing gas first over said tubes 01' said upper group and then through'said outer tubes. the walls of said outer tubes having openings therein for the ejection of cinders thrown out as a result of the centrifugal force caused by the gas flow around said strips.

12. A combined fluid heater and cinder collector, comprising a plurality of substantially parallel, horizontal fluid heater tubes, a wall dividing said tubes into upper and lower groups,

substantially larger outer tubes arranged substantially concentrically around the tubes of said lower group, a cinder hopper below said outer tubes, metal strips wound spirally around the tubesoisaidlowergroupandbetweensameand respective outer tubes, means for flowing through said tubes of through said tubes oi saidubpergroumandmeansi'orming gas passages tor flowing gas flrst over said tubes oi said and then through said outer tubes,

otsaidoutertubesintoaaidgaspassages.

13. A combined fluid heater and cinder collector, comprising a plurality of substantially parallel, horizontal fluid heater tubes, a wall dividing tubes having openings therein for the ejection of cinders thrown out as a result of the centrifugal force caused by the gas flow around said strips, said tubes of said lower group extending substantiallybeyondbothendsotsaidoutertubesinto said gas passages, means forming a gas passage connecting said hopper and the gas exit passage from said outer tubes, and a damper in said last mentioned passage.

THOMAS B. ALLARDICE. 

